SEEING THE WOOD FOR THE TREES:

Dr A B (Tony) Cunningham ICRAF Senior Associate &

School of Plant Biology, University of Western Australia

beyond  bio-­‐for,fica,on:  nutri,on,  cooking  &  health  

OVERVIEW  •  1.  Context  

•  2.  Why  worry  about  what’s  used  for  cooking?  

•  3.  Where  does  solid  fuel  use  for  cooking  occur?  

•  4.  Common  intervenAons;  

•  5.  Fuel  choices,  toxic  effects  &  agroforestry  soluAons  

•  6.  Conclusions.  

•  “Hidden  hunger”  –  micro-­‐nutrient  deficiency;  

•  “nutriAon  transiAon”  &  bioforAficaAon  in  further  dietary  simplificaAon  vs.  biodiversity  in  nutriAon  (Frison  et  al.,  2004,  COP7;  Johns  and  Eyzaguirre.  2007);  

•  Looking  out  of  the  frying  pan  &  into  the  fire….(or  at  fuelwood  &  charcoal  diversity)….  

1.  CONTEXT  

WHAT  SCALE?    CASE  STUDY:  TANZANIA  &  MALAWI  

•  About  half  of  Tanzania’s  annual  consumpAon  of  charcoal  takes  place  in  Dar  es  Salaam  (c.500,000  tons/yr)  from  a  “catchment”  up  to  200  km  away  (WB,  2009);  

•  Tanzania:  trade  worth  US$650  million/yr  (WB,  2009)  &  in  Malawi  c.  US$41.3  million/yr  to  four  ciAes  (=tea  industry)  (Kambewa  et  al,  2007);  

•     Ref:  World  Bank.  2009.  Environmental  crisis  or  sustainable  development  opportunity?:  Transforming  the  charcoal  sector  in  Tanzania.    World  Bank,  Washington  DC.    

2.  BACKGROUND    •  2.4  billion  people  live  in  households  where  solid  biomass  fuels  (wood,  charcoal,  dung)  are  used  for  cooking  &  heaAng  plus  0.6  million  using  coal  (Po  et  al.,  2011);  

•  About  2  million  children/yr  die  of  pneumonia.  Smoke  (=indoor  air  polluAon)  increases  risk  of  pneumonia  by  1.8  in  children  (Dherani  et  al,  2008;  Hu  et  al.,  2010;  Po  et  al.,  2011);  

•  Not  all  woods  are  the  same:  toxins  in  fuelwoods  can  have  serious  health  consequences.  

3.  WHERE  DOES  SOLID  FUEL  USE  FOR  COOKING  OCCUR?  

•  Ref:  Torres-­‐Duque  et  al.  2008.  Biomass  Fuels  and  Respiratory  Diseases.  Proc  Am  Thorac  Soc  5:  577–590  

but  what  about  tree  diversity  &  fuelwood  &  charcoal  quality?  

4.  COMMON  INTERVENTIONS  

•  improvements  of  household  venAlaAon;  

•  IntroducAon  of  different  stove  designs;  

•  TransiAons  to  other  energy  sources  (e.g:  rural  electrificaAon);  

• …but  charcoal  &  fuelwood  sAll  widely  used,  even  with  rural  electrificaAon.  

CASE  STUDY:  SOUTH  AFRICA  

•  electrificaAon  yet  no  significant  decrease  in  per  capita  woody  biomass  consumpAon…BUT:  

•   significant  increase  in  the  Ame  spent  collecAng  fuelwood  &  more  buying  firewood;  

•  larger  number  of  tree  species  collected  &  used  for  fuelwood  than  before…..so  wood  use  will  be  with  us  for  a  while….    

REF:  Madubansi  M  &  Shackleton  C.M.  (2006).  Changing  Energy  Profiles  and  consumpAon  pakerns  following  electrificaAon  in  five  rural  villages,  South  Africa.    Energy  Policy.  34:4081-­‐4092      

5.  FUEL  CHOICES  &  TOXIC  EFFECTS  

• What  is  used  to  cook  foods  by  which  households  &  what  levels  of  exposure  to  what  types  of  smoke?;  

•  Toxic  effects  of  certain  plant  species,  genera  &  families  well  known  (eg:  Spirostachys  (Africa),  Excoecaria  agallocha  (South  Asia)  which  contain  the  diterpene  excoecarin;  

• More  subtle  effects  can  be  more  insidious.  

SMOKE  IS  NATURAL,  BUT  IS  IT  GOOD?  

•  Polycyclic  aromaAc  hydrocarbons  (PAH)  (e.g:  benzopyrenes)  =  carcinogenic  (cancer  of  lungs,  pharynx  &  larynx);  

•  Polycyclic  aromaAcs  &  metal  ions  in  smoke  (toxins  absorbed  into  eye  lenses,  causing  oxidaAve  change  &  cataracts);  

•  Need  to  understand  mutagenicity  emission  potency  of  different  wood  species  are  used  as  fuel.    

SEEING  WOOD,  TREES  &  LANDSCAPES  

less  choice  of  fuelwoods,  parAcularly  for  poor  &  vulnerable  households  

COMBINE  WOOD  MUTAGENIC  ASSESSMENTS  &  LOCAL  KNOWLEDGE

• mutagenic  potency  of  some  fuelwood  species  has  been  established  (e.g:  Vu  et  al.,  2012,  Portugal)  but  more  Asian  and  African  studies  needed;  

•  Good  to  use  informant-­‐based  valuaAon  systems  &  local  knowledge  to  prioriAze  fuelwood  species  (Cunningham,  2001);  

•  Euclea  as  an  example.    

CASE  STUDY:  STRYCHNOS,    5  YR  FAMINE  FOOD  

•  Highly  favoured  woods:  Newtonia  hildebrand9i,  Pteleopsis  myr9folia  vs.  poor  quality  woods  (e.g:  Albizia  versicolor)  (Cunningham,  1985)  

AGROFORESTRY  &  SELECTING  “GOOD  WOODS”  

•  SelecAon  for  chemotypes  with  low  toxic  levels  (e.g:  polycyclic  aromaAc  hydrocarbons)  -­‐  parAcipatory  processes  &  local  knowledge  important    

6.  CONCLUSION:  A  SYSTEMS  APPROACH  

• RestoraAon,  agroforestry  &    Resource  management  

•   availability  of  quanAty  &  quality    of  fruit,  fuel  &  fodder  

species  

FOOD  &  FUELWOOD    AVAILABILITY  

•  Social  networks;  

•   Income  to  buy  food  &  fuel;  •   Disease  impacts  on  capability    (malaria,  respiratory  diseases,  HIV);  •   Direct  &  indirect  impacts    of  climate  on  land-­‐use    

&  food  security.

FOOD  &  FUEL  ACCESS  

• Nutrient  content  of  foods  

(oils,  proteins,  vitamins);    

*  Opportunity  to  boil  water  &  cook  foods;    

• Indirect  effects  on  human  health    &  ability  to  absorb  nutrients    

(fungal  &  fuel  toxins,  water  &  sanitaAon)  

NUTRIENT          ACCESS  

PEOPLE’S  

WELL  BEING  

THANK YOU